The importance of mythical landmarks in hero journeys lies in their role as thresholds and symbols of transformation. These landmarks, such as the Crossroads, the Labyrinth, or sacred mountains, serve as significant points that heroes must navigate to transition from the ordinary to the extraordinary. They provide challenges and guidance, often leading to personal growth and self-discovery. Additionally, these landmarks symbolize the journey's cultural significance, reflecting the values and beliefs of the societies that produced these myths, and often marking pivotal moments that define the hero's quest.